Carburetor



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1: uircu STATES c PATENT OFFICE lJHlESTEtt F.-l'lEENSQlU, F DETRUIT, MICHJIGAN; DETROT ANI) SECURITY TRUST COM- IIPMY EXECUTR F SAID CHESTER F, JOHNSON, DECEASED j CARB'URETOR Application '.lec'l July 22,

rlhis invention relates to carburetors lorl internal combustion engines and has special reference to a simplided and improved mixture controlling device embodying an accelerating fuel supply proportioned to the rapidity and extent of the throttle opening.

lt is an object of this invention to provide an improved and simplified fuel metering control that incorporates a lean' operating range adjustment with a richer maximum adjustment, together with means for varably increasing the duration and extent of an increased opening of the fuel metering control to provide entra fuel for accelerating demands which vary in accordance with the operation of the engine.

lt is another object of this invention tol provide an improved enrichening device for accelerating purposes that will be responsive varying engine requirements as determined by the rapidity and extent of the opening movement of the throttle.

lt is also an object of this invention to provide an improved and simplified carburetor embodying a single fuel nozzle with rneans for controlling the fuel supply thereto in accordance with the varying requirements of starting, maximum economy at part throttle, maximum power at full throttle and acceleratiomtogether with adjustments controlling each of the dierent reuuirements.

@ther and further important objects of this invention will be apparent from the disclosures in the specification and accompanying drawings.

'lhe invention (in a preferred form) is illustrated on the drawings and hereinafter more fully described.

@n the drawings:

Figure 1 is a side elevation of a carburetor with parts broken away to show t-he mixture control means.

Figure 2 is a side elevation of the opposite side of Figure 1, broken away to show the acceleration control means.

Figure 3 is a section on the line lll--llla 1922. Serial N0. 380,174.

ing the application of the present invention i to an offset bowl type of carburetor.

a mining chamber' passage 13, containing a throttle valve 14 on a shaft 15, and terminating in a mounting flange 1G for attachment to the engine. ln Figures 1 to 3 and 6, a fuel passage 17 is centrally mounted in the float bowl and has a restricted nozzle 18 projecting into the throat 19 of a venturi shaped shell 20 forming the primary mixture supply, the air therefor entering a portl 21 into a chamber 22 formed between the carburetor body and the float bowl cover 10a. Y

The restricted nozzle 18 of the fuel passage 1T is provided of a capacity suitable for the maximum acceleration demand, being capable of supply much more than the quantity of fuel required for normaloperation. In order to regulate the fuelsupply for normal operation the lower end of the fuel passage 17 is obstructed by a movably mounted cone 23 which forms the equivalent of a fuel regulating needle valve, this valve being mounted on a lever 24 pivoted at 25. One end 26 of the lever 24 supports a sliding weight 27 which serves to keep the opposite end 28 oi' the lever in contact with a vertically mounted rod 29 in two sections placed end to end. The rod 29 is urged upwardly by a spring 3() into contact with an adjusting screw 31 in a lever 32, which screw forms the high speed adjustment for maximum `power when the throttle is open. For maximum power at full throttle, a cam 33 is mounted upon the throttle shaft in a position to force the lever 24 downwardly by acting through the rod 29 when the 'throttle shaft is rotated towards its full open lll position. The lever 24 may be made, if desired, of thermostatic metals thereby making the fuel re lating needle responsive to temperature c anges of the liquid in the fuel chamber.

At normal or intermediatepositions of the throttle the `cam 33 is turned out of contact with thelever, as shown in Figure 1 and a somewhat leaner mixture is obtained by the upward movement of the rod 29 which decreases the clearance between the needle valve or cone23 and its seat in the end of the tube `17. In order to regulate the economizer adjustment the upward movement of the lever 24, when released by the cam, is limited by an adjusting screw 34 which forms the adjustmentfor the desired quality of fuel and air mixture for maximum economy throughout the partial throttle range. The point of transfer from the economical mixture range to the fulll throttle range is controlled by the position of the cam 33 on the throttle shaft 15, the cam being adjustably clamped on the shaft by a screw 35 in the split hub 36 of the cam.

A dash control is provided comprising a Bowden wire 37 the tube 3 8 of which is clamped at 39, the end of the wire 37 acting against the lever 32 to push it downwardly, thus pushing the needle valve 23 away from its seat through the medium of the lever 28 and the rod 29. This control gives an adjustably richer mixture for starting or driving before the engine has'become warmed up to its normal operatingxtemperature. It is to y be noted that the first part of the dash control movement serves first to enrich that part of the operating range where the mixture 1s normally the thinnest. y I

In order to provide a momentary enrichment of the fuel and air mixture to compensate for the starving that would otherwise occur upon a sudden opening of the throttle to accelerate the engine, I provide a plunger 40, the lower end of which is chambered at 41 yto receive the weight 27 in the chamber. A

light spring 42 may be positioned if desired above the' weight to increase the speed of `Vmovement thereby. The plunger is connec-ted by a link 43 to one of the holes 44 in a lever 45 mounted on the throttle shaft 15, the opening movement of the throttle lifting the plunger 40 and raising the weight 27 due to the suction in the chamber 41, thus allowingthe lever 24 to swing counterclockwise,4

the needle valve 23 being thus withdrawn from the fuel passage 17 to produce an increased fuel supply the limiting amount of which is determined by the nozzle 18. As`

soon as the throttle is checked in its opening movement, the weight 27 slowly returns to its v,position into Contact with the lever end 26,

raising thelever into its normal operating position and cutting ,off the excess'supply of fuel. The length of time required for the return of the weight is dependent upon the freedom or clearance of the weight in the mined by the connection of the link 43. The clearance determines the rapidity of fuel leakage into the chamber 41 as the lower end of the plunger is submerged in the fuel thereby making the movement of the weight slu gish. The position of the link 43 in the ho es 44 of the lever 45 determine the extent ofI movement of the plunger for a full opening of the throttle, and the rapidity of movement of the throttle also modifies the period of the accelerating fuel charge, as a slow opening of the throttle might be such as to coincide in time with the downward movement of the weight in the plunger, in which case no additional opening of the fuel needle would result. This is a highly desirable feature, as the amount of accelerating fuel required varies in an inverse ratio to the acceleration performance demanded, which in turn is determined by the rapidity and extent of opening of the throttle valve.

The modification of Figure 4 is applied to a carburetor having an offset fuel bowl 46 with a bottom outlet 47 having a conduit 48 leading to the throat of the venturi 49 where the conduit is restricted by a nozzle 50 proportioned to restrict the maximum fuel delivery during acceleration. In this case the throttle lever 45, link 43, lplunger, 40 and weight 27 are arranged centrally of the fuel bowl and the lower end of the weight is formed as a valve 51 to control the outlet 47,

-the first described form, so that the same reference numerals have been applied to the structures common to both. In this form the plunger member 54 is externally fluted to be guided within a passage 55, the flutes permitting the flow of fuel past the plunger. A weight 56 is slidably engaged in a chamber in the plunger and has its lower'end formed as a valve 57 which controls the inflow of fuel at a valve seat 58, the weight carrying a pilot 59 which is engaged by an adjusting screw 60 as in the modification of' Figure 4. The plunger 54 is linked directly to an offset lug 61`on the throttle v14 by a rod 62 passing through the venturi 20, the operation of this modification being essentially the same as in the preceding embodiments of the' invention. v

, Figurey 6 illustrates a modification of the .Y plunger -and its distance of travel as detert isol fuel stream to the nozzle 18 when the air llt will thus he seen that in each of the modifications described l have provided an improved and simplified accelerating fuel sup'- ply cooperating with the normal fuel sup ly, the accelerating range and quantity of fuel being subject to the rapidity and extent of throttle movement 'the fuel su ply being dependent upon the suction existing within the carburetor rather than being pumped into the carburetor or manifold regardless of the engine refpiirements.

l am aware that numerous details of construction may be varied through a wide range without departing from the principles of this invention, and ll therefore do not purpose limiting the patent granted, otherwise than necessitated by the prior art.

l claim as my invention:

l.. ln a carburetor, a mixing chamber having a throttle controlled mixture outlet', a fuel nozzle deliverin fuel into said mixing chamber, a fuel cham er supplying said nozzle vvith fuel, a needle valve restricting the flow of fuel into said nozzle, a lever cooperating Awith said needle valve, a weight acting against said lever to normally maintain said needle valve in position, and a plunger operated by said throttle and having a chamber normally enveloping said weight, Whereby the suction in said chamber is adapted to lift said weight upon a sudden upward movement of the plunger toincrease the opening said needle valve. Y

F. ln a carburetor, a mixing chamber having a throttle controlled outlet, a fuel nozzle delivering fuel into said mixing chamber,

u fuel chamber supplying fuel to said nozzle, a needle valve restricting the supply of fuel to said nozzle, a pivoted lever ysrgoporting said needle valve and so balanced as to cause the needle valve to fall away from the ln a carburetor, a mining chamber having a throttle controlled outlet, a fuel noz-V zle deliver-in fuel into said mixing chamber, a fuel c amber supplying-fuel tosaid nozzle, a needle valve restricting the supply of fuel to said nozzle, a pivoted lever supporting said needle valve and so balanced as to cause the needle valve to fall away from the nozzle, means for adjusting the normal position of seid lever, la weight acting against the lever to normally hold the same in position, a

plunger partially enveloping said weight and adaptedyto lift the same by suction upon an upward movement of said plunger, and means connecting said plunger to said throttle whereby an opening movement of said throttle will lift said plunger.

fl. ln a carburetor, a mixing chamber having a' throttle controlled outlet, a fuel nozzle delivering' fuel into said mixing chamber, a fuel chamber supplying fuel to said nozzle, a needle valve restricting the supply of fuel to said nozzle,'a pivoted lever supporting said needle valve and so balanced as to cause the needle valve to fall away from the nozzle, means operated by the throttle for shifting the normal position of said lever to enrichen the mixture, a weight acting against the lever to normally hold the same in position, a plunger partially enveloping said weight and adapted to lift the same by suction upon an upward movement of said plunger, and means connecting said plunger to said throttle whereby an opening movement of said throttle will lift said longer.

5. In a carburetor, a mixing chamber having a throttle controlled outlet, a fuel nozzle delivering fuel into said mixing chamber, a fuel chamber supplying fuel to saidnozzle, a needle valve in said fuel chamber controlling the entrance of fuel to said nozzle, said needle valve being so mounted as to fall away from said nozzle, a weight urging said needle valve towards said nozzle, adjustable means for limiting the upward movement of said needle valve, and means operated by the throttle adapted to lift said Weight by suction imposed thereon by a sudden opening movement of said throttle.

6. ln a carburetor including the fuel supply system and throttle thereof, a fuel nozzle having a capacity sufficient to discharge the maximum quantity of fuel required for accelerating purposes, means for restricting the delivery of fuel for normal operating conditions, an inertia elementassociated with said means, andmeans pneumatically connecting said element with the throttle to be operated by the sudden opening movement thereof to temporarily increase the fuel delivery from said nozzle.

7. lln a carburetor including the float bowl andthrottle thereof, a fuel nozzle delivering fuel from said float bowl and having a capacity sumcient for the maximum acceleration requirements, means for reducing the fuel capacity of said nozzle to' a, point satisfactory for normal operation, said means including a movable memberheld in position by an inertia element, and means connected to the throttle and cooperating with said inertia element to move the same in proportion to the rapidity and vextent of the throttle v'opening movement whereby to temporarily increase the delivery of fuel from said nozzle for accelerating purposes.

8. In a carburetor including the float bowl and throttle thereof, a fuel nozzle delivering fuel from said float bowl and having a capacity suflicient for the maximum acceleration requirements, means for reducing the fuel capacity of said nozzle to a point satisfactory for normal operation, said means 1ncluding a movable member held in position by an inertia element, a plunger partially enveloping said element and adapted to move the same to an extent, dependent upon the rapidity of movement of said plunger, and means connecting said plungerto said throttle whereby anl opening movement of said throttle will lift said plunger.

9. In a carburetor including the float bowl and throttle thereof, a fuel nozzle delivering fuel from said float bowl and having a capacity sufficient for the maximum acceleration requirements, means for reducing the fuel capacity of said nozzle to a point satisfactory for normal operation, said means'including a movable member held in position by an inertia element, a plunger partially enveloping said element and adapted to move o the same upon movement of said plunger, and

means'connecting said plunger to said throttle whereby an opening 'movement ofV saidk throttle will lift said plunger.

10. Ina carburetor, including a mixing.

chamber, a throttle and means forming a fuel supply, a metering nozzle delivering fuel from said fuel'supply to said mixing chamber, means'operable by throttle movement to vary the fuel delivery capacity ofsaid metering nozzle, and accelerating means operated in unison with said throttle and embod ing an inertia elementy temporarily affecte by differential pressure upon a sudden opening ofthe throttle, to alter the normal control of the fuel delivery from said metering nozzle.

1l. In a carburetor, including a mixing chamber, a throttle and means forming a fuel supply, a metering nozzle delivering fuel from said fuel supply to said mixing chamber, means to vary the fuel delivery capacity of said metering nozzle, and accelerating means operated in unison with said throttle and embodying an inertia lelement temporarily affected by differential pressure upon a sudden opening of'the throttle to alter4 the fuel delivery from said metering nozzle.

In testimony whereof I have hereunto subscribed my nameat Detroit, county of Wayne,

Michigan.

CHESTER F. JOHNSON. 

